The biosphere is considered to be the shell of the Earth, inhabited by living organisms, which in the process of their life actively transform it.
Study history
The concept of the biosphere as a field of life was introduced into science by Jean Baptiste de Lamarck in the first half of the 19th century. It was he who came closest to her understanding. But the term itself was proposed by the Austrian scientist Edward Suess. He worked in the field of geology and understood by the biosphere the totality of all organisms. Now such a meaning is embedded in the term “biota”. Suess presented his hypotheses and research results in the famous scientific work “Face of the Earth”, which described the geology of the Alps.
The modern concept of the biosphere was formulated by the Russian scientist geochemist, who has encyclopedic knowledge in many fields of science - Vladimir Ivanovich Vernadsky. As a professor of mineralogy at Moscow University, he became the author of the great work Biosphere, published in 1926. It was in this work that he first gave a detailed definition of this term.
V. M. Vernadsky rightly believed that the biosphere is a large concentric region of the Earth, which plays the role of the main geochemical force. Thus, it is the space in which life exists at the moment or existed ever, that is, the presence of living organisms or their metabolic products is characteristic of the biosphere.
Types of substances in the biosphere
V.I. Vernadsky identified several types of substances that make up the basis of the biosphere.
- Actually living matter, which is formed by a set of organisms.
- A nutrient that forms during and remains after the life of organisms. We are talking about atmospheric gases, coal, oil and more.
- Inert substance that forms without the intervention of organisms.
- Biocosal substance is a compound that is the result of the vital activity of organisms in combination with abiogenic processes.
The boundaries of the biosphere are determined in accordance with the presence of the totality of the above substances in the shells of the Earth.
Living matter in the biosphere
Obviously, the main geochemical and energy processes occur with the obligatory participation of living matter. V. I. Vernadsky formulated the concept of him. Living matter - all living organisms that currently exist, constituting a single totality, which is expressed in elementary chemical composition, weight, energy.
The main property of living matter is its activity, due to the connection with the environment by a constant biogenic flow. The flow is formed during breathing, nutrition, reproduction. In this context, one can consider the vital activity of organisms as a powerful geological process of a planetary nature.
The constant migration of chemical elements between the body and the environment in both directions occurs continuously. The implementation of this process is possible due to the proximity of the elemental chemical composition of organisms to the chemical composition of the earth's crust.
Plants, carrying out photosynthesis, create complex organic molecules in the biosphere that have a large supply of energy. Thus, living matter accumulates and transforms the bound radiant energy of the Sun. The transfer of energy becomes possible due to the constant growth and development of the body. The reproduction rate, as V.I. Vernadsky rightly believed, is the speed at which geochemical energy is transmitted in the biosphere.
Borders
The part of the biosphere in which there are living organisms at present is called the neobiosphere. In other words, modern. And the space that was the habitat of ancient organisms is the paleobiosphere.
The total mass of the geospheres of the planet is approximately 2420 billion tons. This value is 200 times the mass of the atmosphere. Thus, we can conclude that the layer of living matter in the total mass of geospheres is negligible.
The range of potential capabilities and the scale of adaptability of organisms determine the "everywhereness of life." Living things gradually settled in the seas and oceans, then settled on land. According to Vernadsky, the composition and boundaries of the biosphere are changing now.
It should be noted that, unlike other earth shells, only the biosphere can be considered complex. It also performs the function of “cover” from a living entity and is the habitat of many organisms, including humans.
The boundaries of the biosphere are defined as follows. It includes the lower zone of the atmosphere, the upper zone of the lithosphere and the entire hydrosphere. And the heights of the atmosphere, characterized by cold, low pressure, and the depths of the ocean, the pressure in which can reach 12,000 atmospheres, are all the biosphere. The boundaries of the biosphere are so wide due to the very wide limits of temperature tolerance of organisms.
It should be noted that there are bacteria that can exist in a vacuum. The limits of adaptation to chemical conditions are also very wide. The existence of organisms is real, for example, under the constant influence of ionizing radiation. Studies show that some living creatures are so hardy that, according to certain criteria, their capabilities are even outside the biosphere.
In addition to the basic conditions listed, the life of organisms is due to the constancy of the biogenic current of atoms.
The upper boundary of the biosphere
In different parts of the planet, life in the atmosphere exists at different heights. In the zones of the South and North Poles, this value is 8-10 km, near the equator - 17-18 km, over all other territories - 20-25 km. Thus, only the troposphere is filled with life - the lower part of the atmosphere
The physical limit of the distribution of life in the atmosphere is at the lower boundary of the ozone layer.
Hydrosphere
The hydrosphere is formed by oceans, seas, lakes, rivers and ice sheets. At all depths there is life. The vast majority of living organisms occupied the surface layers and coastal areas. But even at a depth of 11,022 m, in the deepest basin of the World Ocean (Mariinsky), there are inhabitants. The neobiosphere also includes bottom sediments, which were once the habitat of ancient creatures.
Lower boundary of the biosphere
If we talk about the lithosphere, then the soil, of course, is its most densely populated layer, but the existence of life is noticed much deeper - about 6-7 kilometers underground. This applies primarily to deep cracks and caves.
Organisms inhabiting the biosphere
Living organisms are divided into two groups depending on the method of obtaining the energy necessary for life: autotrophic and heterotrophic. The habitat of representatives of both groups is the biosphere. The boundaries of the biosphere are determined by their distribution.
Representatives of autotrophic organisms in their diet are not associated with any other living things. For this they need sunlight or the energy of chemical bonds of compounds of inorganic origin. Both that, and another can be used as an energy source, while they receive food from mineral substances.
Autotrophs are divided into two subgroups. These are phototrophs (green) and chemotrophs (bacteria). The former are able to exist only in the area of penetration of sunlight. But the second, due to the use of chemical compounds of organic nature as an energy source, are much more widespread.
Heterotrophs, on the contrary, require organic substances produced by other organisms as sources of energy and nutrition. That is, without the preliminary work of the autotrophs, their existence would be impossible. Animals and humans, as a resident of the biosphere, belong to heterotrophic organisms.
"Films of life"
The uneven distribution of life is one of the important features that characterizes the biosphere. The boundaries of the biosphere have the lowest density of life. The greatest is observed at the junctions of habitats. On the whole, the distribution of life in the biosphere is sharply uneven. V. I. Vernadsky introduced the term “Films of Life”, describing with its help the most densely populated areas of the biosphere. The soil-air contact boundary is the first of these films, its thickness is from 2 to 3 cm. The second is represented by the air-soil contact zone — the coastal strip and upwelling zone. The third is represented by the euphotic zone of the ocean (up to 200 m), i.e., the area of free penetration of the sun's ray.
Thus, life transforming the “face of the Earth” is inextricably linked with the concept of “biosphere”. The boundaries of the biosphere are the boundaries of life.
Spatial-functional organization is a mechanism that provides "the geological eternity of all living things." Man, as a resident of the biosphere, along with other heterotrophic organisms, is a direct participant in the energy cycle that ensures life on Earth.